TTY: switch tty_flip_buffer_push

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/vr41xx_siu.c b/drivers/tty/serial/vr41xx_siu.c
index 62ee016..f655997f 100644
--- a/drivers/tty/serial/vr41xx_siu.c
+++ b/drivers/tty/serial/vr41xx_siu.c
@@ -313,12 +313,10 @@
 
 static inline void receive_chars(struct uart_port *port, uint8_t *status)
 {
-	struct tty_struct *tty;
 	uint8_t lsr, ch;
 	char flag;
 	int max_count = RX_MAX_COUNT;
 
-	tty = port->state->port.tty;
 	lsr = *status;
 
 	do {
@@ -365,7 +363,7 @@
 		lsr = siu_read(port, UART_LSR);
 	} while ((lsr & UART_LSR_DR) && (max_count-- > 0));
 
-	tty_flip_buffer_push(tty);
+	tty_flip_buffer_push(&port->state->port);
 
 	*status = lsr;
 }